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A superconducting cyclotron named CYCIAE-230 is designed and under construction at the China Institute of Atomic Energy, Beijing, China, to provide a 230-MeV proton beam for cancer therapy. The cryogenic system has been completed and the machining of the magnet will be finished soon. The shimming procedure will be performed to obtain the final isochronous field, which requires the field measurement precision to be 5 × 10–5. A search-coil sensor based mapping system was developed to satisfy the measurement accuracy requirements, including a nuclear magnetic resonance probe to precisely measure the field at the cyclotron center and a moving search coil to obtain the field differences. Moreover, a Hall probe is integrated in the system to verify the field data. The system allows the probe motion and data acquisition to be performed automatically. In this paper, the field mapping requirements are listed, the design and calibration of the coil is described, and the field mapping system, including mechanical structure and control system, is presented in detail.

For the applications of proton therapy and proton irradiation, and based on the RD then, the construction progress and the B–H curve measurement results of the warm iron over the magnetic saturation region are outlined; the R&D of the superconducting coils system and the design of the field mapping system are also briefly introduced.

There are very strong demands for mid-energy proton machine in recent years due to the surging cancer patients and fast progress of the space science in China. For the applications of proton therapy and proton irradiation, the energy range of proton beam is usually from 200 MeV to 250 MeV, or even higher for astronavigation. Based on the R&D starting from 2009, a construction project of a 230 MeV superconducting cyclotron (CYCIAE-230) has been launched recently at China Institute of Atomic Energy (CIAE). It was started in Jan 2015, for the program of proton therapy and space science launched by China National Nuclear Corporation (CNNC). In this paper, the designs for the superconducting (SC) cyclotron and its key components, including the main magnet, SC coils, internal ion source and central region, extraction system, etc, and the construction progress of the machine CYCIAE-230 will be presented.

A new project, the 230 MeV proton superconducting synchrocyclotron for cancer therapy, was proposed at CIAE in 2013. A model cavity is designed to verify the frequency modulation trimming algorithm featuring a half-wave structure and eight sets of rotating blades for 1 kHz frequency modulation. Based on the electromagnetic (EM) field distribution analysis of the model cavity, the variable capacitor works as a function of time and the frequency can be written in Maclaurin series. Curve fitting is applied for theoretical frequency and original simulation frequency. The second-order fitting excels at the approximation given its minimum variance. Constant equivalent inductance is considered as an important condition in the calculation. The equivalent parameters of theoretical frequency can be achieved through this conversion. Then the trimming formula for rotor blade outer radius is found by discretization in time domain. Simulation verification has been performed and the results show that the calculation radius with minus 0.012 m yields an acceptable result. The trimming amendment in the time range of 0.328–0.4 ms helps to reduce the frequency error to 0.69% in Simulation C with an increment of 0.075 mm/0.001 ms, which is half of the error in Simulation A (constant radius in 0.328–0.4 ms). The verification confirms the feasibility of the trimming algorithm for synchrocyclotron frequency modulation.

From the stripping points, the high intensity proton beam of a compact cyclotron travels through the fringe field area of the machine to the combination magnet. Starting from there the beams with various energy is transferred to the switching magnet for distribution to the beam line targets. In the design of the extraction and transport system for the compact proton cyclotron facilities, such as the 70 MeV in France and the 100 MeV in China, the space charge effect as the beam crosses the fringe field has not been previously considered; neither has the impact on transverse beam envelope coupled from the longitudinal direction. Those have been concerned much more with the higher beam-power because of the beam loss problem. In this paper, based on the mapping data of 70 MeV cyclotron including the fringe field by BEST Cyclotron Inc (BEST) and combination magnet field by China Institute of Atomic Energy (CIAE), the beam extraction and transport are investigated for the 70 MeV cyclotron used on the SPES project at Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro (INFN–LNL). The study includes the space charge effect and longitudinal and transverse coupling mentioned above, as well as the matching of beam optics using the beam line for medical isotope production as an example. In addition, the designs of the ±45° switching magnets and the 60° bending magnet for the extracted beam with the energy from 35 MeV to 70 MeV have been made. Parts of the construction and field measurements of those magnets have been done as well. The current result shows that, the design considers the complexity of the compact cyclotron extraction area and fits the requirements of the extraction and transport for high intensity proton beam, especially at mA intensity levels.

There are very strong demand for mid-energy of proton machine recent years due to the surging cancer patients and fast progress of the space science in China. For the applications of proton therapy and proton irradiation, the energy range of proton beam usually is from 200 MeV to 250 MeV, or even higher for astronavigation. Based on the R&D starting from 2009, two construction projects of 230 MeV and 250 MeV superconducting cyclotron, which have been implemented recently at China Institute of Atomic Energy(CIAE). That was started in Jan 2015 for the 230 MeV machine, for the program of proton therapy and space science launched by China National Nuclear Corporation (CNNC), and in Jan 2016 for the 250 MeV machine, for the program of proton therapy launched by the Ministry of Science and Technology of China (MOST). In this paper, the designs for the two SC cyclotrons and their key components, including the main magnet, SC coils, RF system, internal ion source and central region, extraction system, etc, and the construction progress of the machines will be presented., Proceedings of the 9th Int. Particle Accelerator Conf., IPAC2018, Vancouver, BC, Canada

The Beijing Radioactive Ion-beam Facility project is being constructed by BRIF division of China Institute of Atomic Energy. In this project, a 100 MeV high intensity compact proton cyclotron is built for multiple applications. The first successful beam extraction of CYCIAE-100 cyclotron was done in the middle of 2014. The extracted proton beam energy is 100 MeV and the beam current is more than 20 μA. The RF system of the CYCIAE-100 cyclotron includes two half-wavelength cavities, two 100 kW tetrode amplifiers and power transmission line systems (all above are independent from each other) and two sets of Low Level RF control crates. Each set of LLRF control includes an amplitude control unit, a tuning control unit, a phase control unit, a local Digital Signal Process control unit and an Advanced RISC Machines based EPICS IOC unit. These two identical LLRF control crates share one common reference clock and take advantages of modern digital technologies (e.g. DSP and Direct Digital Synthesizer) to achieve closed loop voltage and phase regulations of the dee-voltage. In the beam commission, the measured dee-voltage stability of RF system is better than 0.1% and phase stability is better than 0.03°. The hardware design of the LLRF system will be reviewed in this paper.

A 100 MeV H⁻ compact cyclotron is under construction at China Institute of Atomic Energy (CYCIAE-100). The proton beams ranging from 75 MeV - 100 MeV with 200 µA beam intensity will be extracted in dual opposite direction by charge exchange stripping devices. The stripping probe system is the key part of extraction system for CYCIAE-100. The first stripping extraction system was installed in 2014 and it has satisfied all kinds of requirements for the proton beam extraction. The first 100 MeV proton beam was got on July 4, 2014 and the beam current was stably maintained at above 25 μA for about 9 hours on July 25, 2014. The first RIB with ISOL system driven by 100 MeV proton beam was generated in 2015. The second stripping system was installed in 2015 after the assembly and adjustment. The beam commissioning based on the second stripping system will be finished and the extracted proton beam parameters will be measured in detail in this year., Proceedings of the 21st Int. Conf. on Cyclotrons and their Applications, Cyclotrons2016, Zurich, Switzerland

Based on a 10 MeV CRM cyclotron developed at China Institute of Atomic Energy (CIAE) with an achieved beam intensity of up to 430 μA, a 14 MeV high intensity compact cyclotron, CYCIAE-14, was designed and being built at CIAE. It is planned that the first machine would be in place with a span of 2 years. CYCIAE-14 is delicately designed to realize strong vertical focusing by adopting a 4-sector, variable hill-gap structure with an external ion source to achieve high intensity. A special design applied to the stripping extraction gives access to dual extraction with four beams. The adoption of sophisticated industrial technology will give the cyclotron advantages, e.g. low power consumption and high reliability. This paper is aimed to present the overall design of the machine, including the basic technical specifications, main magnet and coils, RF, ion source and axial injection, and stripping extraction, etc. It will also give an introduction to its construction schedule as well as the up-to-date progress.

The 14 MeV, 400 μA compact cyclotron is under construction at China Institute of Atomic Energy (CIAE). The design of main magnet and the result of beam dynamics in the cyclotron will be described in this paper, including the choice of main parameters of magnet, the method of shimming isochronous field in the compact cyclotron and optimization of the magnetic field in central region. The beam will be accelerated to 14.6 MeV by optimizing the magnet structure.

A new radioactive ion beam project, Beijing Radioactive Ion-beam Facility (BRIF), has been started at CIAE since 2004 . In this project, a 100 MeV H- cyclotron, CYCIAE-100, is selected as the driving accelerator providing 75-100 MeV, 200-500 proton beam. CYCIAE-100 is consisting of the main magnet, RF system, ion source and injection system, dual beam extraction system, etc. The progress of this machine had been reported elsewhere . The main magnet is the most critical part and had been numerically simulated and delicately designed . The techniques for main magnet construction are investigated in detail . The construction of this compact style, 450 ton cyclotron magnet has been started since 2007. The imperfection control of the large scale casting steel, the deformation and fabrication tolerance, etc., have all posed a challenge to the capacity limitation of cyclotron lab at CIAE for magnet design, mapping and shimming, and of industry for steel production/machining in the world. The design highlight of the magnet will be briefly introduced and the emphasis in this paper will be given to the construction progress.

The CYCIAE-100 Cyclotron is the main part of the BRIF project at China Institute of Atomic Energy. It is an isochronous compact cyclotron for the acceleration of H-, and it will provide proton beam of 75 MeV ~ 100 MeV with an intensity of 200 ?A ~ 500 ?A. The magnetic pole has the radius of 2000 mm and the magnetic gap is changing gradually from inner radius to outer radius. The maximum filed is 1.3 T and required average isochronous field accuracy is less than 10-4. The difficulties for the design of the magnetic filed measurements device is increased not only due to the field accuracy but also due to the very small space for the compact cyclotron compared with normal machine. This paper describes the field measuring system based on the Hall-probe that has been used for the mapping of field and provides the data for shimming of the cyclotron magnet. The azimuthal and radial position of hall probes will be obtained by optical encoder and linear grating, respective. The overall measurement was estimated to be in the range of ±0.01%.

CYCIAE-100, a 100 MeV H-cyclotron under construction at China Institute of Atomic Energy, is a compact H-cyclotron. Since its upper/bottom and return yokes are each made of a casting steel of large dimension (with final dimension of 6160 mm in diameter and weight of 140 tons each piece), special attention has to be paid to the annealing procedure to insure the magnetic properties of this kind of large scale casting steel pieces with high purity. First, this paper presents an overview of annealing strategies to improve the magnetic properties of large scale casting steel. Then an estimation of heating time during annealing procedure has been made by FEM simulation based on the current status of annealing facility in China and has been indirectly verified by a rule of thumb from the results in TRIUMF design note. Based on that as well as on a close collaboration with CITIC HMC, the manufacturer of large casting steel mill, an agreement on detailed annealing procedure has been reached and issued for production of large casting steel for CYCIAE-100. The results from the practice have been obtained and the detail procedure will be presented in this paper as well.

The beam dynamics behaviour in the compact cyclotron central region is investigated. The design study for central region, including the spiral inflector, Dee tip, shield and posts, for three cyclotrons at CIAE will be described in this paper. The code development by CIAE and the UNIX based codes developed by TRIUMF were implemented on WINDOWS/PC by CIAE for the spiral inflector and central region design will be given too.

A 100 MeV H-compact cyclotron is being designed in China Institute of Atomic Energy (CIAE). It will provide a 75–100 MeV, 200–500 μA proton beam for various applications, including serving as a driving accelerator for RIB generation. In this paper, the basic magnet structure, 3D numerical simulation, magnetic material, mechanical design, deformation, imperfection field. will be described in detail respectively. In addition the preparation for construction will be discussed.

The construction of a 100-MeV high-intensity cyclotron, from which proton beam will be extracted through stripping to several proton beam lines for different users, has been completed at China Institute of Atomic Energy. Given that it is the H-ions that are to be accelerated in the machine, the peak field is only 1.35 T. To simplify the fabrication, the pole adopts straight sector instead of the spiral one. Meanwhile, vertical focusing should be sufficiently high to obtain high-current proton beam. All these demands make it particularly difficult for the design and fabrication of the main magnet, which is heavy in weight and challenging to meet precision requirement in fabrication. In the process, we have developed a high-performance parallel computation PIC code for beam dynamics of high-current cyclotrons and for FFAGs, which can be used for beam dynamic simulation at a very precise level. The result is then applied to guide the design, fabrication, installation, magnetic mapping, and shimming of the 416-ton main magnet with a precision requirement up to 0.05 mm. Another challenge is due to the deformations of the magnet without/with the vacuum. The whole map measured in the vacuum has to be completed in such a big machine for the first time in the world. The result shows that all requirements, including the isochronous field, vertical focusing, and imperfection fields, have been satisfied properly. The first beam and the stable beam for an 8-h commissioning test had been achieved on July 4 and July 25, 2014, respectively.

POOSL (Parallel Object-Oriented Specification Language) is a powerful general purpose system-level modeling language. In research on design space exploration of motion control systems, POOSL has been used to construct models for performance analysis. The considered motion control algorithms are characterized by periodic execution. They are executed by multiple processors, which are interconnected by Rapid Input/Output (RapidIO) packet switches. Packet latencies as worst-case latencies and average-case latencies are essential performance criteria for motion control systems. However, POOSL analysis merely allows for estimation results for these latency metrics since it is primarily based on simulation. Because motion control systems are time-critical and safety-critical, worst-case latencies of packets are strict timing constraints. Therefore exact worst-case latencies are to be determined. Motivated by this requirement we propose to use model checking techniques. In this paper we illustrate how a POOSL model of a (simplified) motion control system can be transformed into an UPPAAL model and we verify its functional behavior and worst-case latencies. Moreover, we show that analysis of average-case latencies can also be accomplished with assistance of the model checking tool UPPAAL.

Schedulability analysis of real-time system has been a central focus of research in scheduling theory and a remarkable progress is made in recent years. This progress provides the opportunity to integrate these state of the art results into real-time networks, so that the analysis time for the feasibility of periodic messages is reduced. In this paper, we employ such advancement in the widely studied IEEE 802.5 protocol for scheduling real-time packets. Our technique avoids false points, the point (time) at which a particular packet is not schedulable, that arise during feasibility analysis and eventually the analysis is done more efficiently.

In line with the increasing demand for PET cyclotrons in China, the construction of a 14 MeV high intensity compact cyclotron, CYCIAE-14, has been proposed at China Institute of Atomic Energy (CIAE) in 2010 and is scheduled to be finished within two years. The fabrication is in smooth progress, with a majority of the devices ready in place for installation. As a critical part of the cyclotron, the main magnet development is of paramount importance to the successful development of the machine. At present, the main magnet design and fabrication has been accomplished. The physics design of the main magnet, which enables the realization of strong focusing by adopting a 4-sector structure with variable hill gap, will be emphatically introduced in the paper. Meanwhile, the engineering techniques applied to the fabrication will also be presented, in particular the technical challenges encountered in the process. Based on the accomplishment of two sets of main magnets, six more sets of main magnets will be fabricated.

A comprehensive test stand for high-intensity cyclotron development, a 10 MeV 430 μA cyclotron, has been successfully constructed at China Institute of Atomic Energy (CIAE) for the experimental verification of the viability of a 100 MeV high-intensity cyclotron (CYCIAE-100) being constructed at CIAE. The verification includes the overall design technology, detail design and engineering technology for the crucial parts of the machine, e.g. main magnet and beam diagnostics. It will also pave the way for future enhancement of the beam intensity. The test stand consists of a H− ion source, axial injection system, central region, main magnet and coil, RF resonator, stripping extraction, and auxiliary systems, which include the RF power amplifier, high voltage and DC power supplies, electric apparatus, beam diagnostics, control, vacuum, water cooling, pneumatic system, and safety interlock. This paper presents the work regarding the design and sub-system development of the test sand, and the results of the beam commissioning of the machine.